Facility · X-ray lasers
PAL-XFEL
X-ray free-electron laser on a 10 GeV normal-conducting S-band linac at 60 Hz, with hard (HX1) and soft (SX1) X-ray lines
- Status
- Operating
- Location
- Pohang, Republic of Korea
- Operator
- Pohang Accelerator Laboratory (POSTECH)
- Next
- 2026 funding for the second hard X-ray line HX2 has started; no start date announced
Summary
Korea's X-ray free-electron laser: 10 GeV electrons, an undulator of about 100 m, 60 Hz. Hard X-rays 0.06–1 nm (2.2–15 keV at the beamline), soft X-rays 1–10 nm (250–1,200 eV) (PAL, beamlines). The first phase built HX1 and SX1; the design allows for three hard (HX1–HX3) and two soft (SX1–SX2) lines. Stations: XSS (FXS, FXL) and NCI (CXS, SFX) on the hard X-ray line; XAS/XES (since 2017), RSXS (since 2020) and FTH (since 2021) on the soft X-ray line.
Now as of 9 Nov 2026
According to the plenary talk at LINAC2026 (Daejeon, 17 August 2026), the machine runs stably at 10.5 GeV, and funding for the second line, HX2, started in 2026: 1.5–10 keV, more than 3 mJ between 1.5 and 8 keV (twice HX1), 20 undulators with self-seeding, and two new stations. The hard and soft X-ray lines will run simultaneously at 60 Hz each; a resonant kicker (about 50 MHz, as at SwissFEL) separates two bunches about 25 ns apart (LINAC2026, MO1A001, slides). A PAL poster at the same conference gives HX2 as 2–10 keV at 180–200 pC and 30 Hz (MC2.A04), so the parameters are still being refined. The IPAC'23 plan put HX2 construction at about two years and about USD 100 million (IPAC'23 PAPU); no official start date has been given.
Key dates
- 2017First user station on the soft X-ray line (XAS/XES)done
- 2026Funding for HX2 beginsdone (linac2026)
- ≈ 2028HX2 starts operationestimate from the ipac'23 plan (about two years)
Timeline
- 17 Aug 2026LINAC2026: HX2 funded from 2026; operating mode with several lasers running at once — slides